Dr. Breus, one of the World's Leading Sleep Doctors, discusses the importance of Vitamin D for a healthy and natural sleep. The best source for Vitamin D is sunlight. Vitamin D from food like salmon, tuna, eggs, and mushrooms is also a natural healthy source. All part of a healthy sleep regimen of sleep, diet, and exercise. Enjoy the article and have a salmon omelette with mushrooms!

We're nearing the end of what's been a long winter for people in many parts of the United States. In the middle and northern regions of the U.S., where winter brings not only cold but limited sun, people aren't only deprived of warmth, they also may be deficient in an important nutrient: Vitamin D.

The body actually produces its own Vitamin D, in response to exposure to sunlight. For this reason, Vitamin D isn't actually considered a vitamin at all, but rather is classified as a hormone. Besides sun exposure, people also receive Vitamin D through foods -- fatty fish and fish oils, egg yolks, as well as fortified foods like dairy and juice -- and also from supplements.

Unfortunately, many people don't maintain sufficient levels of Vitamin D--and this can lead to health complications. It's estimated that 50 percent or more of adults and children may be deficient in Vitamin D, which is now widely recognized as a public health problem.

Vitamin D is critical to the body's mental and physical function. It assists the body in absorbing calcium and phosphorus, and contributes to bone health. Healthy levels of Vitamin D may help with weight loss and weight management. Research suggests that low levels of Vitamin D are associated with higher risks for several serious diseases, including cancer, diabetes, cardiovascular disease, and multiple sclerosis. Insufficiency of Vitamin D is also linked to greater risk for depression and other mood disorders. In healthy people, maintaining higher levels of Vitamin D may offer protection against these same conditions.

Vitamin D may also be important for maintaining healthy sleep. Recent research indicates that Vitamin D may influence both sleep quality and sleep quantity. Researchers analyzed the sleep patterns and Vitamin D levels among a group of older adult men, and found that Vitamin D deficiency was associated with less sleep overall and also with more disrupted sleep. The study included 3,048 men ages 68 and older. Researchers measured Vitamin D serum levels using a blood test. They measured sleep using wrist actigraphy, recording measurements of total sleep time, wake time after sleep onset, and sleep efficiency--a measurement that results from comparing time spent in bed to the time actually spent sleeping.

Among participants, 16 percent had low levels of Vitamin D. To identify the possible influence of Vitamin D over sleep, researchers controlled for several other factors, including age, season of the year, other health conditions, body-mass index, and both physical and cognitive function. They found that low levels of Vitamin D were linked to several problems with sleep:

•Low Vitamin D increased the likelihood that participants experienced insufficient sleep, sleeping less than five hours a night.
•Low levels of Vitamin D were linked to lower sleep efficiency scores, and a greater chance of scoring below 70 percent. A healthy sleep efficiency score is generally considered to be 85 percent or higher.

A lower sleep efficiency score is an indicator of difficulties with sleep quality, as well as perhaps with sleep quantity. A low sleep efficiency score may mean it takes a long time to fall asleep or may indicate waking very early. A low sleep efficiency can also mean sleep is fragmented and restless, with many awakenings throughout the night.

This study is noteworthy because it appears to be the first study to objectively show that Vitamin D deficiency has negative effects on sleep. Other research has demonstrated links between low levels of Vitamin D and sleep problems. But these studies have measured sleep subjectively, using survey data and reports from participants who assess their own sleep, in terms of both quality and quantity. This study measured sleep using objective tools -- specifically wrist sensors -- before analyzing that data in relation to levels of Vitamin D.

Overall, there's not been enough research devoted to this relationship--likely a complicated one -- between Vitamin D and sleep. The results of this study ought to encourage more attention and focus on this relationship and its potential influence over long-term health.

What's the best way to increase your Vitamin D? There's no better source than the sun. Direct sun exposure to skin triggers the synthesis of Vitamin D. But sun exposure can't always be relied upon for a steady, consistent source of Vitamin D. There are a number of factors that can influence how effectively sun exposure can trigger Vitamin D production in the body, including air pollution, time of day, season of the year, and level of cloud cover. Sunscreen and clothing can also impede the effects of sun exposure for Vitamin D. People with higher levels of skin pigmentation absorb less of the UVB rays necessary to begin the synthesis of Vitamin D, and may be more likely to have low levels as a result. Older adults are also at greater risk for low Vitamin D levels.

Protecting your skin from excessive sun exposure is important--I am not suggesting you abandon wearing sunscreen. But some limited time in the sun without sunscreen to allow for Vitamin D production may be useful for health, and for sleep. The recommendations for sun exposure to boost Vitamin D generally fall in the range of 5-10 minutes of exposure, from a few times a week to daily.

Adding Vitamin D rich and fortified foods to your diet can also help increase levels. Fatty fish like salmon, tuna, swordfish, and sardines are all excellent sources of Vitamin D. So are eggs. Many dairy products, including milk and yogurt, are fortified with Vitamin D, as are citrus juices and many cereals. Supplements are another important option to help you maintain healthy Vitamin D levels, especially for people who are at high risk for deficiency, because of age, ethnicity, health conditions, or where they live.

The best way to know if your Vitamin D levels are low is to have your physician perform a blood test. If like so many people, your levels are low, you and your doctor can put together a plan that may include diet, controlled sun exposure, and supplements, to bring levels up and make sure they stay that way. Maintaining sufficient levels of Vitamin D is good for overall health wellness, and likely also to be good for your sleep.

In this recent article the case is made for the importance of both quality and duration of sleep. Sleep is mandatory for human beings. There are several important items about achieving great sleep. 1. Follow a sleep regimen (dark cool room, set times for sleep and wake, limit caffeine and alcohol, etc.) 2. 5 Complete REM sleep cycles per night which typically is 8 hours of sleep. 3. Sleep in a comfortable mattress.

The article, below offers some great tips. Enjoy!

Not getting enough sleep is detrimental to both your health and productivity. Yawn. We've heard it all before. But results from one study impress just how bad a cumulative lack of sleep can be on performance. Subjects in a lab-based sleep study who were allowed to get only six hours of sleep a night for two weeks straight functioned as poorly as those who were forced to stay awake for two days straight. The kicker is the people who slept six hours per night thought they were doing just fine.

This sleep deprivation study, published in the journal Sleep, took 48 adults and restricted their sleep to a maximum of four, six, or eight hours a night for two weeks; one unlucky subset was deprived of sleep for three days straight.

Subjects who got six hours of sleep a night for two weeks straight functioned as poorly as those who were forced to stay awake for two days straight.
During their time in the lab, the participants were tested every two hours (unless they were asleep, of course) on their cognitive performance as well as their reaction time. They also answered questions about their mood and any symptoms they were experiencing, basically, "How sleepy do you feel?"

WHY SIX HOURS OF SLEEP ISN'T ENOUGH
As you can imagine, the subjects who were allowed to sleep eight hours per night had the highest performance on average. Subjects who got only four hours a night did worse each day. The group who got six hours of sleep seemed to be holding their own, until around day 10 of the study.

In the last few days of the experiment, the subjects who were restricted to a maximum of six hours of sleep per night showed cognitive performance that was as bad as the people who weren't allowed to sleep at all. Getting only six hours of shut-eye was as bad as not sleeping for two days straight. The group who got only four hours of sleep each night performed just as poorly, but they hit their low sooner.

The six-hour sleep group didn't rate their sleepiness as being all that bad, even as their cognitive performance was going downhill.
One of the most alarming results from the sleep study is that the six-hour sleep group didn't rate their sleepiness as being all that bad, even as their cognitive performance was going downhill. The no-sleep group progressively rated their sleepiness level higher and higher. By the end of the experiment, their sleepiness had jumped by two levels. But the six-hour group only jumped one level. Those findings raise the question about how people cope when they get insufficient sleep, perhaps suggesting that they're in denial (willful or otherwise) about their present state.

WE HAVE NO IDEA HOW MUCH WE SLEEP
Complicating matters is the fact that people are terrible at knowing how much time they actually spend asleep.
According to the Behavioral Risk Factor Surveillance System survey, as reported by the CDC, more than 35% of Americans sleep less than seven hours in a typical day. That's one out of every three people. However, those who suffer from sleep problems don't accurately estimate how much they sleep each night.

If you think you sleep seven hours a night, as one out of every three Americans does, it's entirely possible you're only getting six.
Research from University of Chicago, for instance, shows that people are as likely to overestimate how much they sleep as underestimate it. Another sleep study published in Epidemiology, indicates people generally overestimate their nightly sleep by around 0.8 hours. The same study also estimates that for every hour beyond six that people sleep, they overestimate sleep by about half an hour. If you think you sleep seven hours a night, as one out of every three Americans does, it's entirely possible you're only getting six.

So no one knows how much or little they're sleeping, and when they don't sleep enough, they believe they're doing better than they are.

Even just a little bit of sleep deprivation, in this case, six rather than eight hours of sleep across two weeks, accumulates to jaw-dropping results. Cumulative sleep deprivation isn't a new concept by any means, but it's rare to find research results that are so clear about the effects.

FIXING SLEEP: EASIER SAID THAN DONE
Figuring out how to get enough sleep, consistently, is a tough nut to crack. The same advice experts have batted around for decades is probably a good place to start: Have a consistent bedtime; don't look at electronic screens at least 30 minutes before bed; limit alcohol intake (alcohol makes many people sleepy, but it can also decrease the quality and duration of sleep); and get enough exercise.

Other advice that you'll hear less often, but which is equally valid, is to lose excess weight. Sleep apnea and obesity have a very high correlation, according to the National Sleep Foundation. What's more, obese workers already suffer from more lost productive time than normal weight and overweight workers.

Other causes of sleep problems include physical, neurological, and psychological issues. Even stress and worry can negatively affect sleep. The CDC has called lack of sleep a health problem, and for good reason. Diet, exercise, mental health, and physical health all affect our ability to sleep, and in return, our ability to perform to our best.

Fixing bad sleep habits to get enough sleep is easier said than done. But if you're functioning as if you hadn't slept for two days straight, isn't it worthwhile?

Jill Duffy is a writer covering technology and productivity. She is the author of Get Organized: How to Clean Up Your Messy Digital Life.